Business forms, particularly mailer type business forms, having pressure sensitive cohesive (such as the type shown in U.S. Pat. Nos. 4,918,128 and 5,427,851 and sold commercially by Toppan Forms Ltd. of Japan under the trade designation TN-124), are becoming increasingly popular because of the significant advantages associated with the use of pressure activated cohesive as opposed to heat activated adhesive or rewettable adhesive. One of many examples of business forms utilizing this pressure activated cohesive is shown in U.S. Pat. No. 5,201,464 (the disclosure of which is hereby incorporated by reference herein). A wide variety of different types of pressure sealing equipment, such as that sold by Moore North America, Inc. under the trademark "SpeediSealer".RTM. has been developed for utilization with such forms, typically such equipment having at least two sets of in-line pairs of pressure-seal rollers to apply a sealing force of at least about 100 pounds per lineal inch to effect proper sealing of folded forms, having the cohesive thereon. Much of this equipment is expensive, however, and particularly the pressure-seal rollers themselves can be very expensive. Therefore, there has been a desire to reduce the complexity and expense of such equipment particularly for low or mid-volume installations.
One prior art pressure seal piece of equipment that is greatly simplified, using only two pressure-seal rollers in association with a reversible motor, is disclosed in U.S. Pat. No. 5,133,828 (the disclosure of which is hereby incorporated by reference herein). While that equipment is very useful, it is impractical to automate, the forms do not pass completely through the nip between pressure-seal rolls before they are reversed during normal operation and therefore sometimes one edge of the form may not be sealed as securely as desired, and the sealer is distinct from the folding equipment for folding business form intermediates (such as in U.S. Pat. No. 5,201,464) into folded business forms (e.g. mailers). According to the present invention an apparatus and method are provided which allow for automation, or at least semi-automatic operation, of simplified pressure seal equipment, pass the forms completely through the nip between pressure seal rollers during operation, may be placed immediately at the output (or near the output) of the folder, and in one embodiment even comprise part of the folder so that one of the pressure-seal rollers functions both to effect folding and sealing. Despite these advantages, the apparatus according to the invention comprises only two rollers, or in the embodiment where a portion of the conventional folder has been eliminated only three pressure-seal rollers, so that the equipment is simple and relatively inexpensive.
According to one aspect of the present invention a pressure sealing apparatus for acting on business forms having pressure activated cohesive, to seal the cohesive, is provided. The apparatus comprises: First and second pressure-seal rollers rotatable about substantially parallel first and second axes of rotation, respectively, and in operative association with each other so as to define a nip which supplies sufficient pressure so as to activate pressure activated cohesive on a business form passing through the nip. Drive means for driving at least one of the pressure-seal rollers to effect movement of a business form completely through the nip. And holding means for holding a business form having pressure activated cohesive in a position distinct from the nip but so that the business form will substantially automatically be engaged by and pass through the nip upon operation of the drive means.
In one embodiment the holding means may comprise a primarily vertically disposed chute positioned with respect to the nip so that a business form within the chute and not within the nip will be biased at least partly by gravity toward or into contact with one of the pressure-seal rollers or the nip.
In one embodiment using a chute, the drive means comprises reversible drive means (such as a reversible electric motor or any other conventional type of drive) for driving at least one of the pressure-seal rollers alternatively clockwise and counterclockwise, and the pressure-seal rollers consist essentially of (only) first and second rollers. The apparatus may further comprise a business form folder having a discharge disposed substantially immediately below the nip on the opposite side thereof from the chute, so that folded business forms are fed by the folder into the nip.
The apparatus may still further comprise a diverter positioned adjacent the folder discharge for diverting sealed forms passing through the nip from the chute away from the folder.
In another embodiment using the substantially vertical chute, the pressure-seal rollers consist essentially of (only) the first and second rollers and a third roller rotatable about a third axis of rotation substantially parallel to the first and second axes of rotation, and in operative association with the first roller so as to define a second nip which supplies sufficient pressure so as to activate pressure activated cohesive on a business form passing through the second nip. This embodiment may further comprise a business form folder, including a first folder roller rotatable about a fourth axis of rotation substantially parallel to the third axis, and operatively positioned with respect to the third pressure-seal roller and first and second fold plates so that the third roller effects folding of a business form passing between the third pressure-seal roller and the first folder roller, and effects sealing of the business form when passing from the second fold plate through the second nip. In the embodiment the business form folder may consist essentially of (only) the first folder roller, a second folder roller on the opposite side of the first folder roller from the third pressure-seal roller, the third pressure-seal roller, the first and second fold plates, and a feed table for feeding business forms to be folded into a nip between the first and second folder rollers.
The pressure-seal rollers may be positioned with respect to each other so that imaginary lines passing through the axes of rotation thereof have substantially an L-shape. The drive means (such as a conventional electric motor, or any other conventional type of drive) may drive the pressure-seal roller continuously in a first direction of rotation. While the rollers may provide only edge seal, in a preferred embodiment the pressure-seal rollers each have a substantially continuous constant diameter peripheral surface having a length sufficient to engage substantially all surface area of a business form face brought into contact therewith.
The holding means may take a wide variety of other forms aside from the vertically disposed chute, and/or the vertically disposed chute may have spring leafs, elastic portions, or other elements associated therewith for properly retaining the form. For example, the holding means may comprise spring leaves spring pressed into engagement with each other, or any other suitable conventional device for properly holding a business form or sheet of paper in a releasable manner in a particular location. For example, the holding means may comprise a pair of idler nip rollers, particularly where the drive means comprises reversible drive means for driving at least one of the pressure-seal rollers alternately clockwise and counterclockwise, wherein the pressure-seal rollers consist essentially of the first and second rollers. The holding means may further comprise a conveyor having a business form-engaging conveying surface extending substantially transverse to the pressure-seal rollers and substantially in alignment with the nip and idler nip wheels. For example, the conveyor may comprise a belt conveyor driven by a reversible drive and positioned to assist in feeding a business form to be sealed into the nip and into association with the idler nip wheels. In this embodiment typically the pressure-seal roller axes are substantially vertical; and the structure further comprises a forms guide positioned in association with respect to the belt conveyor to guide forms into contact with the belt conveyor to be fed to the nip, the forms guide mounted on the opposite side of the nip from the idler nip wheels. The apparatus may further comprise a forms deflector mounted with respect to the nip and constructed so as to allow a business form within the forms guide to pass through the nip into contact with the idler nip wheels, but will deflect the business form away from the forms guide when passing from the idler nip wheels through the nip. In this embodiment too while the rollers may comprise edge seal rollers, preferably the pressure-seal rollers each have a substantially continuous constant diameter peripheral surface having a length sufficient to engage substantially all surface area of a business form face brought into contact therewith.
According to another aspect of the present invention a pressure-seal apparatus is provided comprising the following components: Pressure-seal rollers consisting essentially of first and second pressure-seal rollers rotatable about substantially parallel first and second axes of rotation, respectively, and in operative association with each other so as to define a first nip; and a third pressure-seal roller rotatable about a third axis of rotation substantially parallel to the first and second axes of rotation, and in operative association with the first roller so as to define a second nip. The pressureseal rollers are positioned with respect to each other so that imaginary lines passing through the axes of rotation thereof have substantially an L-shape. Holding means located above the first nip for holding a folded sheet after it has passed through the second nip in such a manner that the trailing edge of the folded sheet is forced to follow the surface of the first roller as it rotates, thereby introducing the trailing edge into the first nip, where it becomes the leading edge of the folded sheet. And drive means for driving at least one of the rollers to effect movement of a folded sheet through the nips.
The invention also relates to a method of handling a business form having patterns of pressure activated cohesive, using first and second fold rollers, and first, second and third pressure-seal rollers, first and second fold plates, and a holding device above the first and second pressure-seal rollers. The method may comprise substantially automatically: (a) Feeding a business form (e.g. an unfolded intermediate) between the first and second fold rollers and into the first fold plate, to introduce a first fold therein. (b) Feeding the form from the first fold plate to between the first fold roller and the third pressure-seal roller and then to the second fold plate to introduce a second fold therein. (c) Feeding the form from the second fold plate to between the third and first pressureseal rollers to effect activation of pressure activated cohesive on the form, and to the holding device above the first and second pressure-seal rollers. And (d) feeding the form from the holding device to between the first and second pressure-seal rollers to effect activation of pressure activated cohesive on the form so that the form is held in folded condition. The folding may be C-fold, Z-fold, or a double fold, eccentric or uniform.
In the method, (a)-(d) may be the only operations necessary for effective folding of the business form and sealing of the folded business form. The method may further comprise (e), after (d), diverting the form from between the first and second rollers to a stack. The method may also further comprise spring pressing the third and second pressure-seal rollers into contact with the first pressure-seal roller to provide a sealing pressure between both the third and first pressure-seal rollers, and first and second pressure-seal rollers, of at least about 100 pounds/lineal inch. Also, the method may further comprise driving only the first pressure-seal roller, the third and second pressure-seal rollers being driven by engagement with the first pressure-seal roller. In the practice of the method the pressure-seal rollers may each have a substantially continuous constant diameter peripheral surface having a length sufficient to engage substantially all surface area of a business form face brought into contact therewith; and (c) and (d) may be practiced to apply a pressure of at least about 100 (e.g. 100-200) pounds/lineal inch across substantially the entire surface of the folded form.
According to yet another aspect of the invention there is provided a method of handling a business form having patterns of pressure activated cohesive, using first and second pressure-seal rollers defining a nip there between, and a holding device above the nip between the first and second pressure-seal rollers, comprising substantially automatically: (a) Feeding a folded business form from a folder into the nip from below the nip. (b) Driving one or both of the pressure-seal rollers to move the form up through the nip into the holding device while activating pressure activated cohesive on the form. And (c) after the form has passed completely through the nip, reversing the direction of rotation of the pressure-seal rollers to move the form downwardly through the nip to effect activation of pressure activated cohesive on the form so that the form is held in folded condition.
In this aspect of the invention, the method may further comprise (d) diverting the form away from the folder as the form is passed downwardly during the practice of (c). In fact (d) may be practiced by moving a diverter automatically in response to reversing the direction of rotation of the pressure-seal rollers. In the practice of the method the pressure-seal rollers may each have a substantially continuous constant diameter peripheral surface having a length sufficient to engage substantially all surface area of a business form face brought into contact therewith; and (b) and (c) may be practiced to apply a pressure of at least about 100 pounds/lineal inch across substantially the entire surface of the folded form.
According to still another aspect of the invention there is provided a method of handling a business form having patterns of pressure activated cohesive, using first and second pressure-seal rollers rotatable about substantially vertical axes and defining a nip therebetween, and a holding device on a second side of the nip opposite a first side, comprising substantially automatically: (a) Feeding a folded business form to a first position on the first side of the nip. (b) Moving the form substantially horizontally into the nip. (c) Driving one or both of the pressure-seal rollers to move the form substantially horizontally through the nip into contact with the holding device while activating pressure activated cohesive on the form. And (d) after the form has passed completely through the nip, reversing the direction of rotation of the pressure-seal rollers to move the form back toward the first side of the nip through the nip to effect activation of pressure activated cohesive on the form so that the form is held in folded condition.
In this aspect of the method, there may further comprise (e) automatically diverting the form away from the first position during the practice of (d). Also, (a) may be practiced by effecting guided substantially downward movement of the folded form while the form is in a substantially vertical plane.
It is the primary object of the present invention to provide a simple yet effective method and apparatus for substantially automatically sealing, or folding and then sealing, business forms having pressure activated cohesive. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.